Cascaded multipole switches for single-mode and multimode optical fibres

Multistage moving-fibre array switches which use preferentially etched silicon chips for the precise alignment of the optical fibres have been developed. In particular, a 1×4 single mode, and a 1×8 multimode fibre switch are described, with which average insertion losses of 0.8 and 0.2 dB were achieved, respectively.